Abstract Several small Butler matrices are interconnected in a manner to replace a large single Butler matrix employed in a beam forming and scanning network for a linear array. This system of Butler submatrices (a set of low order Butler matrices simulating a single higher order Butler matrix) permits reduction in the size of existing feeding systems, which results in a substantial savings of system components and hardware. The function of this submatrix feed system is substantially identical to that of the single multibeam matrix network in most respects except for a fewer number of available beams. Also, this submatrix feed system is capable of exciting linear arrays which cannot presently be excited by a single Butler matrix. Also, the system has application in satellite communications and direction finding equipment.
In a beam forming and scanning network for a linear array of antennas, each antenna being connected to an output of multibeam network means, a plurality of the input means of said multibeam means being serially coupled to fixed phase shifters and power dividers, the improvement comprising: a plurality of discrete Butler matrices employed as said multibeam network means between the antennas and fixed phase shifters.
Claim 2
Dependent Claim
66 words
In a beam forming and scanning network for a linear array of antennas, each antenna being connected to an output of multibeam network means, a plurality of the input means of said multibeam means being serially coupled to fixed phase shifters and power dividers, the improvement comprising: a plurality of discrete Butler matrices employed as said multibeam network means between the antennas and fixed phase shifters.
Claim 3
Dependent Claim
82 words
In a beam forming and scanning network for a linear array of N antennas, each antenna being connected to an output terminal of multibeam network means, a plurality of input beam terminal means of said multibeam network means being serially coupled to fixed phase shifters and power dividers, the improvement comprising: B number of (C X C) order discrete Butler submatrices having C number of outputs employed as said multibeam network means between the antennas and fixed phase shifters wherein B.N N.
Claim 4
Dependent Claim
82 words
In a beam forming and scanning network for a linear array of N antennas, each antenna being connected to an output terminal of multibeam network means, a plurality of input beam terminal means of said multibeam network means being serially coupled to fixed phase shifters and power dividers, the improvement comprising: B number of (C X C) order discrete Butler submatrices having C number of outputs employed as said multibeam network means between the antennas and fixed phase shifters wherein B.N N.
Claim 5
Dependent Claim
92 words
The device as claimed in claim 2 wherein the first terminal of each submatrix is sequentially connected across the linear array until the first terminal of submatrix B is connected to terminal B of the array and, the B + 1 element of the array is connected to the second terminal of the first submatrix and; the second terminal of each subsequent submatrix is sequentially connected until the second terminal of submatrix is connected to array element 2B; and until the C terminal of submatrix B is connected to array element N.
Claim 6
Dependent Claim
41 words
The device as claimed in claim 2 wherein the fixed phase shifter comprises: B-1 sets of prescribed line lengths for establishing a phase: where k is the particular beam terminal of said multibeam means, and SMn is the particular submatrix means.
Claim 7
Dependent Claim
11 words
The device as claimed in claim 2 wherein: B equals 2.